Python, Bool property without Load UI behaviour?
There is an AddonPreferences example here. It even has a bool property.

Access this property and display it anywhere like this (for example Panel's draw method):

def draw(self, context):
    layout = self.layout

    user_preferences = context.user_preferences
    addon_prefs = user_preferences.addons[__name__].preferences

    layout.prop(addon_prefs, "boolean")

    if addon_prefs.boolean:
        layout.label(text="checkbox is on")
    else:
        layout.label(text="checkbox is off")